in Sri Lanka - Ministry of Environment

Bruggen is restricted to the lowland wet zone and Endangered (EN). However, although notendemic, A. natans (L.) Engler & Krause and A. crispus Thunb. are both considered as rareand threatened due to over exploitation in the wild and are in the Vulnerable category (VU).Podostemaceae is a family with plants of very unusual vegetative form. Seven members arerecorded in the country with two endemics. They are more or less thalloid, growing on rocksin fast-flowing rivers or cataracts and could be considered a highly threatened group of plants.The rapids of the Mahaweli river at Gannoruwa-Hallolluwa area, Kandy provid the habitat forsix of these species including the endemics. Both endemics, Farmeria metzgerioides (Trimen)Willis ex Hook.f. and Polypleurum elongatum (Gardner) J.B.Hall are considered as Vulnerable(VU),while Polypleurum stylosum (Wight) J.B. Hallis is listed as Critically Endangered (CR).However, Zeylanidium lichenoides (Kurz) Engl., recorded as confined to the river rapids of themontane region, is now considered under Probably Extinct category (CR(PE)).Two aquatic carnivorous plant families are recorded in the island. The family Droseraceaeincludes insectivorous herbs with leaves set with sticky glandular hairs holding down anddigesting insects. Drosera burmanni Vahl and D. indica L. show a wider distribution but arestill recognized under the Vulnerable category (VU) due to threats on its habitats, while D.peltata Smith, restricted to the highlands, especially Nuwara Eliya and Badulla districts, islisted under Endangered category (EN). The genus Utricularia (Lentibulariaceae) harborsfifteen carnivorous herbs with specialized organs (traps/bladders) to capture and digest smallorganisms. Utricularia moniliformis P. Taylor is the only endemic member listed under theVulnerable category (VU) and is restricted to Kandy and Nuwara Eliya districts while the otherspecies show a wider distribution in lowland dry and wet zones. However, due to the habitatdisruption, many of the native species have also been affected; seven of them are now listedunder various categories during the present Red Listing.ThreatsThe aquatic ecosystems have been affected throughout the history by various anthropogenicthreats, habitat deterioration/degradation, over exploitation of species and alien invasions. TheDirectory of Asian Wetlands (Scott, 1989) documents several threats where siltation has beena frequently reported threat for the listed wetland sites of the island. Considering differentecosystems, the aquatic ecosystem is unique as it is vulnerable to direct human activities aswell as many indirect human activities that are distant-based rather than on-site.Habitat deterioration/degradation: Habitat deterioration/degradation is caused by on-siteactivities as well as distant-based human activities. The aquatic ecosystems are vulnerablemostly due to the latter. Kotagama and Bambaradeniya (2006) identified reclamation, clearingof vegetation, water pollution (through organic pollution, other chemical effluents and sewagedisposal), regulation of water flow, unplanned irrigation structures and mining as the majorcauses for wet land deterioration/degradation. Reclamation for infrastructure development,construction of aquaculture ponds, more recently due to security reasons and further dumpingof domestic and municipal waste have affected wetlands, especially those in urban areas suchas Bellanwilla-Attidiya marsh (CEA/ Euroconsult, 1993). This site is one of the recorded sitesfor Critically Endangered endemic sedge Eleocharis lankana T. Koyama, confined to lowlandmarshes. Illegal reclamation for human settlement, dumping of garbage, chemical pollution190